WASHINGTON—Republicans narrowly chose House Majority Whip Tom Emmer (R., Minn.) as their nominee for speaker, moving to end a three-week-old political crisis by picking a candidate who they hope could finally garner a majority of the chamber and win the gavel.

Weary from weeks of fighting and embarrassing setbacks, House Republicans picked Emmer over fellow finalist Rep. Mike Johnson (R., La.), the vice chairman of the House Republican conference, following a rapid-fire series of votes to choose from an initial group of more than a half dozen hopefuls. The tally in the final round was 117 for Emmer to 97 for Johnson.